you mean upgrade via system update? you can't choose which version to update to, it will give you 4.3. if you have hbc 1.0.8 it will survive, you cios'es will be stubbed and you'll have to reinstall them. if you are currently on 4.1 there is no point updating, 4.2 and 4.3 are just anti-piracy updates. all you need is ios58 for usb2.0 and maybe ios56 and shop channel v20 to access shop channel. if you must, use one of the stickied guides in this forum to update to 4.2.